IE45461B1

IE45461B1 - Improvements in or relating to a laminate

Info

Publication number: IE45461B1
Application number: IE1656/77A
Authority: IE
Original assignee: Dart Ind Inc
Priority date: 1976-09-02
Filing date: 1977-08-08
Publication date: 1982-08-25
Also published as: DE2739211C2; CA1107625A; AR212725A1; ES461999A1; AU498588B2; FR2363437B1; IL52689A0; NL172423C; BE858285A; NO773029L; SE7709864L; DE2739211A1; NZ184929A; LU77972A1; IE45461L; IL52689A; DK389777A; MX147055A; NL172423B; FR2363437A1

Abstract

A process is disclosed for producing a decorative laminate which comprises applying a polyester resin to a decorative sheet, curing the resin, preparing an assembly of superimposed sheets by placing the decorative sheet upon a dry sheet, placing beneath the dry sheet a plurality of thermosetting resins impregnated sheets and consolidating the assembly under heat and pressure to form a unitary laminated structure. The high pressure decorative laminate obtained has exceptional stain and chemical resistant properties.

Description

The present invention relates to laminates and more particularly to cured resin products formed by lamination techniques, Countertops for all typos of laboratories, beauty 5 shops, pharmacies, and many other commercial and industrial premises must be stain and chemical resistant in addition to being wear and impact resistant. Typically such countertops are constructed of slate, marble, composition stone, or black or grey coloured wood surfaces covered with a varnish. Of course, the slate and marble are heavy, difficult to install, and expensive. The painted wood counters are readily scratched or abraded and require frequent maintenance. Surfaces coated with a cured polyester resin have exceptional chemical resistance properties, and are also wear resistant. However, unless such surfaces are bonded to a high density substrate or the like, they will lack impact strength and are not very durable. Melamine/formaldehyde resin laminates provide a good Wear and impact resistant surface which can also be decorative but lack the ability to resist chemical attack.

An attempt to overcome this problem is shown in U.S. Patent 3,756,901 wherein a fibre glass sheet and a heavy kraft paper are impregnated with polyester resins to produce a low pressure laminate. The kraft paper must have a basis weight of greater than 140 pounds to 4S461 - 3 produce a laminate having adequate impact resistance.

U. S. Patent 3,929,545 discloses a similar low pressure polyester laminate, but this product is generally suitable for vertical applications wherein impact and wear resistance are not important factors. ϋ. S. Patent 3,551,241 discloses a lay-up comprising corestock impregnated with phenolic resin, a decorative sheet impregnated with melamine/foxmaldehyde resin, and a top release sheet coated with polyester resin. The lay-up is consolidated under high temperature and pressure conditions. Of course, the final product is a strong rigid laminate but lacks wear resistance and suffers delamination defects because of the immisclbility and resultant lack of good bond between a polyester resin and a melamine/formaldehyde resin.

The present invention seeks to provide a laminated product and method for manufacturing the same which can offer decorative patterns and/or colour choices in combination with exceptional chemical and stain resistance.

According to one aspect of this invention there is provided a process for producing a decorative laminate comprising the steps of applying a polyester resin to a decorative paper sheet and partially curing said resin; subsequently preparing an assembly of superimposed sheets by placing said, decorative paper sheet upon a dry paper sheet, placing a plurality of thermosetting resin impregnated paper sheets beneath said dry sheet and consolidating said assembly under heat and pressure to form a unitary laminated structure.

According to a further aspect of this invention there is provided a process for producing a decorative laminate comprising the steps of applying a polyester resin to a decorative paper sheet and partially curing the resin, placing beneath the decorative sheet a plurality of thermosetting resin impregnated paper sheets, Β 4 61 - 4 said thermosetting resin being separated from said cured resin by a dry sheet portion comprising either a part of said decorative sheet, or a dry paper sheet interposed between said decorative sheet and said resin impregnated sheets, and consolidating the assembly with heat and pressure to form a unitary laminated structure.

According to another aspect of this invention there is provided ε process for producing a decorative laminate comprising the steps of applying a polyester resin to the face surface of a decorative paper sheet to impregnate the sheet and drying the polyester resin, coating a release sheet with a polyester resin and partially curing the resin coating on the release sheet, preparing an assembly of superimposed sheets by placing the release sheet upon the decorative paper sheet with the resin coating of the release sheet in contact with the face surface of the decorative paper sheet, placing the decorative paper sheet on a dry paper sheet and placing a plurality of thermosetting resin impregnated paper sheets beneath said dry paper sheet, consolidating said assembly under heat and pressure to form a unitary laminated structure, and removing the release sheet from said structure.

According to yet another aspect of this invention there is provided a process for producing a decorative laminate comprising the steps of applying a polyester resin to the face surface of a decorative paper sheet, allowing a portion of said resin to penetrate into said sheet a distance less than the thickness thereof and drying said resin, coating a release sheet with a polyester resin and partially curing the resin coating on the release sheet, preparing an assembly of superimposed sheets by placing the release sheet upon the decorative paper sheet with the resin coating of the release sheet in contact with the face surface of the decorative sheet 4 61 - 5 and placing a plurality of thermosetting resin impregnated paper sheets beneath said decorative sheet, consolidating said assembly under heat and pressure to form a unitary laminated structure, and removing the release sheet from said structure.

It is also to be noted that the phrase curing the resin to a B stage refers to the process of partially curing the resin to a semi-solid state to provide a non-mobile film. Attention is directed to U.S. Patent No. 3,929,545 which describes apparatus for curing a resin to a B stage. It is to be appreciated that the precise degree of curing in any care is dependent on the proposed use to which the laminate is to be put, the degree of curing being relatively low where a laminate having a high degree of flexibility is required and the degree of curing being relatively high where a laminate having a low degree of flexibility is required.

It is to be understood that the term dry paper sheet refers to a paper sheet which has not been impregnated with a thermosetting resin and the term dry sheet portion refers to a portion of a paper sheet which has not been so impregnated.

A preferred product in accordance with the invention is a high pressure laminate wherein the desirable properties of transparency, chemical resistance and wear resistance produced with a polyester resin surface layer are synergistically combined with the desirable strengthening features of melamine formaldehyde and phenolic resin impregnated substrate layers. The immiscibility and delamination defects common in prior art laminations are overcome with the use of an intermediate dry paper sheet between the polyester resin layers and the melamine (melamine/formaldehyde) and/or phenolic resin impregnated substrate layers. During lamination, each of the respective resins on opposite sides of the dry 43401 • · - . - 6 paper sheet penetrate therein a certain distance. In this manner, the immiscible resins are integrally bound together with the dry paper sheet to form a unitary final product having the combined desirable features of both resin systems. Alternatively, it is envisaged that a partially impregnated decorative paper sheet having a dry portion in contact with the melamine formaldehyde and/or phenolic resin impregnated substrate layers would also function to bond the immiscible resin layers together.

In order that the invention may be more readily understood and so that further features thereof may be appreciated the invention will now be described by way of example.

In a first method in accordance vzith the invention a release sheet that has been coated with a “B staged polyester resin is placed upon a polyester impregnated decorative paper sheet. The decorative paper sheet is placed upon a dry paper sheet which has not been subjected to a treating or coating procedure. This assembly is then consolidated under heat and pressure with various types of thermosetting resin impregnated paper substrate sheets. At the conclusion of the consolidation step, the release sheet is removed.

To describe the procedure in more detail, the said first method calls for the use of a flexible release sheet upon which is applied a polyester resin film. The release sheet may be any one of a plurality of commonly used materials such as a cellulose film (typically of the type sold under the Trade Mark Cellophane) polyester film, aluminium foil, or foil-paper laminates. Additionally, papers which have been coated or treated with polyethylene, polypropylene, polyfluorocarbon materials, silicone, or other release materials may be utilised to enhance the release of the film from the sheet. It will - 7 also be appreciated that the release sheet may be textured so that it can impart an embossed surface finish to the surface of the finished laminate.

The polyester resin used for coating the release sheet consists of substantially 100% by weight of reactive solids. Particular polyester resin mixtures which may be used arc. described in U. S. Patent 3,756,901 to which Specification the reader is specifically directed. Apparatus suitable for use in curing the resin to a semisolid B stage is described in 0. S. Patent 3,929,545 to which Specification the reader is specifically directed. Generally, the resin contains about 65% by weight polyester resin and 35% by weight styrene monomer. These components are mixed with photoinitiators or U.V. light sensitizers and peroxide and are supplied to the release sheet by a conventional reverse roll coating apparatus. The film thickness is generally controlled to be between about 5 and 20 mils. The coated sheet is passed through an ultraviolet light processor wherein U.V. light operates to cure the resin to a semisolid state. The speed of the coated sheet through the processor and the number of U.V. lamps and distance of the lamps from the sheet are important variables in achieving the semi-cured non-mobile film referred to as a B stage cure. As the coated release sheet moves away from the processor, the partially cured film is interleaved with a polyethylene film for temporary storage prior to its use in the aforementioned lay-up.

The decorative paper sheet used in this embodiment of the present invention is saturated to contain from 4063% by weight and preferably between 48% and 52% by weight of resin solids. To achieve this, a polyester resin mixture is prepared containing 85-95% by weight resin and 5-15% by weight vinyl monomer. To this mixture are added catalysts, inhibitors, and silica 4S461 - 8 materials to control the melt viscosity and flow characteristics of the fluid. A viscosity between 150 and 500 centipoise is produced by adding a solvent such as acetone and/or methyl ethyl ketone.

The decorative paper sheet is fed into a vat containing the solvent resin system, and the amount of resin applied to the sheet is controlled by feeding the wetted sheet through metering rolls. The impregnated sheet is dried in a heated oven to remove a substantial portion of the volatile solvents. Generally, the dried sheet should not contain more than between 4% and 6% by weight volatiles. As the sheet exists from the drying oven, it is cooled and interleaved with a plastics material film and wound on a continuous roll for temporary storage until further processing into a final laminated product.

A final| laminate assembly is prepared by arranging in a stacked relationship a plurality of substrate paper sheets which have bean Impregnated with a thermosetting resin. Over the substrate sheets is placed an overlay that has been impregnated with a thermosetting resin such as melamine formaldehyde. This overlay may be in fact a barrier sheet depending upon the colour and/or type of sheet being utilised.

Above the barrier and/or melamine formaldehyde treated overlay is a dry paper sheet, and immediately above the dry paper sheet is the polyester impregnated decorative paper sheet. The coated release sheet is placed upon the impregnated decorative paper sheet with the 11B staged polyester coating in direct contact with the decorative paper sheet. The entire assembly is placed into a conventional laminating press and is heat and pressure consolidated to a final unitary laminated structure. The pressure is generally from 800-1200 PSI with a temperature range of from 225°-325°F.

The overall thickness of the final laminate product -iS 161 produced by the above-described method can be controlled by the number of substrate sheets used.

A second method in accordance with the present invention for producing the chemically resistant high pressure laminate involves the direct coating of a dry decorative paper sheet with a thermosetting polyester resin. The coated . asin is B staged to a semisolid stage and subsequently bended to various substrate materials as described in connection with the first method. This method has the advantage of providing the decorative sheet with a coating of cured polyester resin in fewer steps than were used in the production of the previously described decorative laminate.

In particular, the second method involves the reverse roll coating of a decorative paper sheet with a heat curable polyester resin -of the type used in the first method for coating the release sheet. In this instance, however, the coating thickness is increased to about 1130 mils. The coating is cured by passing the material through the U.V. processor in the same manner as that described with reference to the first method. Upon exiting the processor, the partially cured polyester film is interleaved with a plastics material sheet and wound into rolls for temporary storage, or it can be immediately cut into sheets for use in the lay-up of a final laminate.

It will be appreciated that upon application of the polyester film to the surface of the decorative paper Sheet, a portion of the resin will penetrate the surface of the sheet. The resin content can be from 60-90% by weight of the partially cured sheet but generally, the preferred resin content is between 75% and 85% by weight of the partially cured impregnated sheet with a volatile content of between 2% and 6% by weight. A laminate assembly based upon the second method is prepared by placing, in a stacked relationship, a plurality of resin 43461 - 10 treated substrate paper sheets above which is placed a resin treated paper barrier or overlay sheet. Over the barrier or overlay sheet is placed a dry paper sheet and the polyester coated and impregnated decorative sheet is placed upon this. The entire assembly is consolidated as previously described in conventional high pressure laminating press.

To achieve a more complete understanding of the present invention, the following examples are set forth.

It will be appreciated, however, that these examples are primarily for the purpose of illumination and/or illustration and specific details contained therein should not be interpreted as a limitation on the invention.

EXAMPLE 1 An isophthalic polyester resin is prepared containing 88.7% by weight Ashland Chemical Company's 7200 polyester resin and 11.3% by weight vinyl monomer (diallyl phtalate). To this is added; 1% by weight t-butyl perbenzoate, 1% by weight benzoyl peroxide, 250 PPM (.025% by weight) BHT inhibitor, and 3.77% by weight Cab-O-Sil { Trade Mark) M5 (Cabot Corporation) fumed silica. These ingredients are added to a solvent blend of acetone and methyl ethyl ketone in a proportion resulting in a final viscosity between 150-500 centipoise.

A decorative alpha cellulose sheet is fed under tension into a vat containing the above described resin and passed betwe'en metering rolls which control the resin content in the paper. The saturated sheet is then force air dried in a steam heated oven containing graduated temperature zones. The amount of volatiles in the exiting sheet is controlled between 4% and 6% by weight whereas the resin solids as a proportion of the total impregnated sheet Is controlled between 48% and 52% by weight. The exiting sheet is cooled and interleaved with polyethylene film and wound into a continuous roll. - 11 An aluminium foil release sheet is coated with a polyester resin consisting of Ashland Chemical Company's 7200 resin in styrene (65% by weight alkyd, 35% by weight styrene). To these reactive solids are added 1% by weight photoinitiator, “Trigonal ( Trade Mark) 14 (Noury Chemical Company), 0.75% by weight t-butyl perbenzoate, 800 PPM (.08% by weight) Pluronic ( Trade Mirk) L122 surfactant (BASF Wyandotte Corporation) and 500 PPM (.05% by weight) BHT inhibitor. The aluminium foil release sheet is passed over a reverse direction roll coater. A layer of the above described polyester resin controlled at a film thickness of about 12-14 mils is applied. The coated release sheet is then passed through a U.V. processor in which untraviolet light is emitted from 200 watts per inch mercury vapour lamps operating at 1500 volts and 7.5 amps. The line speed is about 8 feet per minute per lamp with the lamps about 6 inches above the film. Upon exiting the U.V. processor, the resultant B staged cured polyester film is interleaved with a polyethylene film and wound into a roll for storage.

Predetermined lengths of the coated release sheet and decorative paper layer are layed-up with resin impregnated per substrate sheets in a conventional laminating press and consolidated between 800-1200 PSI and 270° - 312°F for about 35 minutes. The laminate is cooled for about 25 minutes and removed from the press.

The following order of lay-up produced a unitary laminate structure which exhibited physical properties in excess of comparable NEMA standard values with a chemical and stain resistance which far exceeded conventional melamine-formaldehyde high pressure laminates: 4S46i.

Polyester coated and U.V. B staged release sheet Polyester Pre-Preg 50% resin content Dry paper overlay Melamine-formaldehyde treated barrier 40-50% by weight 5 resin content Il-Phenolic treated kraft paper sheets 35-38% by weight resin, 122 lb basis wt.

Melamine-formaldehyde treated overlay-70% by weight resin content EXAMPLE 2 Example 1 is repeated except that the lay-up is: Polyester coated and U.V. B staged release sheet Polyester Pre-Preg 50% by weight resin content Dry paper overlay Melamine-formaldehyde treated overlay-70% by weight resin content 11-Phenolic treated kraft paper sheets 34-38% by weight resin content, 122 lb basis wt.

Melamine treated overlay-70% by weight resin content EXAMPLE 3 Example 1 is repeated except that the lay-up is: Polyester coated and U.V. B staged release sheet Polyester Pre-Preg 50% by weight resin content Polyester barrier sheet 40-50% by weight resin content Dry paper overlay Melamine-formaldehyde treated overlay-70% by weight resin content 11-Phenolic treated kraft paper sheets 34-38% by weight resin, 122 lb basis wt.

Melamine-formaldehyde treated overlay-70% by weight resin content EXAMPLE 4 Example 1 is repeated except that the lay-up iss Polyester coated and U.V. B staged release sheet Polyester Pre-Preg 50% by weight resin content Dry paper overlay Melamine-formaldehyde treated overlay-70% by weight resin content 11-Phenolic treated kraft paper sheets 34-38% by weight resin, 122 lb basis wt.

Melamine-formaldehyde treated overlay-70% by weight resin content EXAMPLE 5 Example 1 is repeated except that the lay-up is: Polyester coated and U.V. B staged release sheet Polyester Pre-Preg 50% by weight resin content Dry paper overlay Melamine-formaldehyde treated barrier 40-50% by weight resin content 3-Phenolic treated kraft paper sheets 40% by weight resin content, 132 lb basis wt.

Dry crepe Dry paper sheet - 14 EXAMPLE 6 Example 1 is repeated except that the lay-up is: Polyester coated and U.V. B staged release sheet Polyester Pre-Preg 50% by weight resin content Dry paper overlay Melamine-formaldehyde treated overlay-70% by weight resin content 3-Phenolic treated kraffc paper sheets 40% by weight resin content, 132 lb basis wt.

Dry crepe Dry paper sheet EXAMPLE 7 Example 1 is repeated except that the lay-up is: Polyester coated and U.V. Bn staged release sheet Polyester Pre-Preg 50% by weight resin content Polyester barrier sheet 40-50% by weight resin content Dry paper overlay Melamine-formaldehyde treated overlay-70% by weight resin content 3-Phenolio treated kraft paper sheets 40% by weight resin content, 132 lb basis wt.

Dry crepe Dry paper sheet EXAMPLE 8 Example 1 is repeated except that the lay-up is: Polyester coated and U.V. B staged release sheet •j 3 4 61 - 15 Polyester Pre-Preg 50% by weight resin content Dry paper overlay Melamine-formaldehyde treated overlay-70% by weight resin content 3-Phenolic treated kraft paper sheets 40% by weight resin content, 132 lb basis wt.

Dry crepe Dry paper sheet EXAMPLE 9 An example of a lamina··-2 produced by the second method is as follows: An isophthalic polyester resin solution having a viscosity between 1000 and 2000 centipoise is prepared consisting of Ashland Chemical Company's 7220 resin, 1% by weight Triganol ( Trade Mark) 14 (Noury Chemical Company), 0.75% by weight t-butyl perbenzoate, 800 PPM (.08% fcy weight) Pluronic ( Trade Mark) surfactant (BASF Wyandotte Corporation) and 500 PPM (.05% by weight) BHT inhibitor. A decorative alpha cellulose sheet is passed over a reverse direction roll coater containing the above described resin and wherein a film thickness of approximately 17-20 mils is applied. The speed of the coater is controlled so that a small amount of saturation of the resin in the sheet takes place during the time the sheet travels the distance between the roll coater and curing source. B stage curing is accomplished with the U.V. processor described in Example 1.

The B staged decorative sheet may be interleaved with a polyethylene sheet and rolled for storage or it may be immediately cut into predetermined lengths and processed into a decorative laminate.

The procedure is to form an assembly by superI imposing the polyester resin impregnated decorative sheet with resin impregnated substrate materials as follows: UV .B staged polyester coated decorative paper 75-85% by weight resin content Dry paper overlay Melamine-formaldehyde treated barrier 40-50% by weight resin content 11-Phenolic treated kraft paper sheets 34-38% by weight resin content, 122 lb basis wt.

Melamine-formaldehyde treated overlay-70% by weight resin content The above lay-up is consolidated into a unitary structure as described in Example 1. The laminate structure exhibited physical properties in excess of comparable NEMA standard values with a chemical and stain resistance which far exceeded conventional melamineformaldehyde high pressure laminates.

EXAMPLE 10 The method of Example 9 is repeated except that the lay-up is: UV B staged polyester coated decorative paper 75-85% by weight resin content Polyester barrier sheet 40-50% by weight resin content Dry paper overlay Melamine-formaldehyde treated barrier 40-50% by weight resin content 11-Phenolic treated kraft paper sheets 34-38% by weight resin content, 122 lb basis wt.

Melamine-formaldehyde treated overlay-70% resin content >43461 - 17 EXAMPLE 11 The method of Example 9 is repeated except that the lay-up is: ' UV B staged polyester coated decorative paper 75-85% by weight resin content Dry paper overlay Melamine-formaldehyde treated overlay-70% by weight resin content 11-Phenolic treated kraft paper sheets 34-38% by weight resin content, 122 lb basl3 wt.

Melamine-formaldehyde treated overlay-70% by weight resin content EXAMPLE 12 The method of Example 9 is repeated except that the lay-up is: UV B staged polyester coated decorative paper 75-85% by weight resin content Polyester barrier sheet 40-50% by weight resin content Dry paper overlay Melamine-formaldehyde treated overlay-70% by weight resin content 11-Phenolic treated kraft paper sheets 34-38% by weight resin content, 122 lb basis wt.

Melamine-formaldehyde treated overlay-70% by weight resin content EXAMPLE 13 The method of Example 9 is repeated except that the lay-up is; 4546! - 18 UV B staged polyester coated decorative paper 75-85% by weight resin content Dry paper overlay Melamine-formaldehyde treated barrier 40-50% by weight resin content 3-Phenolic treated kraft paper sheets 40% by weight resin content, 132 lb by wt.

Dry crepe Dry paper sheet EXAMPLE 14 The method of Example 9 is repeated except that the lay-up is: UV B staged polyester coated decorative paper 75-85% by weight resin content Polyester coated carrier sheet 40-50% by weight resin content Dry paper overlay Melamine-formaldehyde treated barrier 40-50% by weight resin content 3-Phenolic treated kraft paper sheets 40% by weight resin content, 132 lb basis wt.

Dry crepe Dry paper sheet EXAMPLE 15 The method of Example 9 is repeated except that the lay-up iss UV ’’B staged polyester coated decorative paper 75-85% by weight resin content Dry paper overlay - 19 Melamine-formaldehyde treated paper overlay 70% by weight resin content 3-Phenolic teated kraft paper sheets 40% by weight resin content, 132 lb basis wt.

Dry crepe Dry paper sheet EXAMPLE 16 The method of Example 9 is repeated except that the lay-up is: UV ’’Β staged polyester coaled decorative paper 75-85% by weight resin content Polyester coated paper barrier 40-50% by weight resin content Dry paper overlay Melamine-formaldehyde treated paper overlay 70% by weight resin content 3-Phenolic treated kraft paper sheets 40% by weight resin content, 132 lb basis wt.

Dry crepe Dry paper sheet A third method for producing the laminate of the present invention concerns the use of a decorative paper sheet partially impregnated with polyester resin. The decorative sheet will be coated on its face side with the polyester resin.

Impregnation will occur with resin penetration into the sheet a distance less than its full thickness.

The sheet will be layed-up with its back dry side in contact with melamine-formaldehyde resin impregnated paper overlay or barrier sheet layers. During lamination 3-361 - 20 the melamine-formaldehyde resin will migrate into the dry portion of the decorative paper sheet thereby forming a bond with the polyester impregnated portion of the decorative paper sheet.

It will be understood that the polyester resin formulations may be the same as those set forth in Examples 1 and 9 above. It is desirable, however, to adjust the viscosity of the polyester resin to a level between 300 and 3000 centipoise to inhibit the complete saturation of the decorative sheet. Preferred viscosity range adjustments of 700-3000 centipoise are readily affected by the amount of solvents and/or thixotropic agents utilized.

It will also be appreciated that impregnation of the decorative paper sheet is affected by the basis weight, thickness, surface finish porosity and/or saturation characteristics thereof. Additional factors are the speed through the curing oven or U.V. processor whereby the slower the speed, the more time the resin will have to penetrate the paper fibrous structure. Of course, the melamine-formaldehyde impregnated sheet will have sufficient resin to flow into the dry portion of the decorative sheet. A 35-55% by weight resin content range will usually be sufficient.

EXAMPLE 17 An example of a laminate produced by the third method is as follows: An isophthalic polyester resin is prepared containing 88.7% by weight Ashland Chemical Company's 7200 polyester resin and 11.3% by weight vinyl monomer (diallyl phthlate). To this is added: 1% by weight tbutyl perbenzoate, 1% by weight benzoyl peroxide, 250 PPM (.025% by weight BHT inhibitor, and 4.8% by weight Cab-O-sil ( Trade Mark) M5 (Cabot Corporation) fumed silica. These ingredients are added to 454 61 - 21 a solvent blend of acetone and methyl ethyl ketone in a proportion resulting in a final viscosity about 1500 centipoises. A 90 lb basis weight decorative alpha cellulose sheet is coated on its decorative face side with a reverse direction roll coater containing the above-described resin. The film applied is then dried in an oven having graduated temperature zones as described in Example '. The exiting sheet has a resin content between 30% and 60% by weight with volatiles held to less than 5% by weight.

Predetermined lengths of the partially saturated decorative sheet are layed-up and consolidated with the polyester coated and U.V. B staged release sheet (as set forth in Example 1) as follows: Polyester coated and U.V. staged release sheet Polyester Pre-Preg decorative sheet, 37% by weight resin content Melamine-formaldehyde treated barrier sheet 55% by weight resin content 11-Phenolic treated kraft paper sheets 35-40% by weight resin content, 122 lb basis wt.

EXAMPLE 18 The procedure of Example 17 was followed with a lay-up as follows: Polyester coated and U.V. B staged release sheet Polyester Pre-Preg decorative sheet 42% by weight resin Melamine-formaldehyde treated paper overlay 50% by weight resin 7-Phenolic treated kraft paper sheets 34-38% by weight resin Melamine-formaldehyde treated paper overlay-65% by - 22 45461 weight resin EXAMPLE 19 The procedure of Example 17 was followed with a lay-up as follows: Polyester coated and U.V. B staged release sheet Polyester Pre-Preg decorative paper sheet 46% by weight resin Melamine-formaldehyde treated paper overlay 48% by weight resin 9-Phenolic treated kraffc paper sheets 35% by weight resin Dry crepe Dry paper sheet EXAMPLE 20 An isophthalic polyester resin solution having a viscosity between 1000 and 2000 centipoise is prepared consisting of Ashland Chemical Company's 7220 resin, 1% by weight Trigonal ( Trade Mark) 14 (Noury Chemical Company), 0.75% by weight t-butyl perbensoate, 800 PPM (.08% by weight) Pluronic ( Trade Mark) surfactant (BASE Wyandotte Corporation) and 500 PPM (.05% by weight) BHT inhibitor.

A 65 lb basis weight decorative alpha cellulose sheet is coated on its face surface with the above described resin solution to a thickness of about 15-20 mils. B stage curing is accomplished with the U.V. processor described in Example 1. Predetermined lengths of the coated decorative sheet are layed-up in the following order and consolidated us described in Example 1: Polyester decorative sheet that has been coated with 1530 20 mils of U.V. B staged polyester resin - 23 48461 Melamine-formaldehyde treated paper overlay-55% by weight resin content -Phenolic treated kraft paper sheets, 42% by weight resin, 132 lb basis weight Dry crepe Dry paper sheet EXAMPLE 21 Example 20 is repeated with the following lay-up: Polyester decorative sheet that has been coated as in Example 20 Melamine-formaldehyde treated paper overlay-50% by weight resin 11-Phenolic treated kraft paper sheets-40% by weight resin, 122 lb basis wt.

EXAMPLE 22 Example 20 is repeated with the following lay-up: Polyester decorative sheet that has been coated as in Example 20 Melamine-formaldehyde treated paper barrier sheet 48% by weight resin 3-Phenolic treated kraft paper sheets-44% by weight resin, 132 lb basis wt'.

Melamine-formaldehyde overlay-70% by weight resin Laminates prepared as described in the examples above had physical properties above NEMA standard values and displayed stain and chemical resistance in excess of conventional melamine-formaldehyde high pressure laminates.

Claims

1. CLAIMS;1. A process for producing a decorative laminate comprising the steps of applying a polyester resin to a decorative paper sheet and partially curing said resin; 5 subsequently preparing an assembly of superimposed sheets by placing said decorative paper sheet upon a dry paper sheet, placing a plurality of thermosetting resin impregnated paper sheets beneath said dry sheet and consolidating said assembly under heat and pressure to 10 form a unitary laminated structure.

2. A process according to claim 1 wherein said polyester resin impregnates substantially the entire decorative sheet.

3. A process according to claim 1 or 2 wherein 15 a melamine-formaldehyde impregnated paper sheet is positioned directly beneath said dry paper sheet. , 4. A process according to any one of the preceding claims wherein said polyester resin is cured to a semi-solid state by radiation. 20 5. A process according to claim 2 or any claim dependent thereon wherein the polyester resin content of said decorative sheet after the partial curing of said resin is 50-50% of the total weight. S. A process for producing a decorative laminate 25 · comprising the steps of applying a polyester resin to the face surface of a decorative paper sheet and allowing a portion of said resin to penetrate into said sheet a distance less than the thickness thereof; partially curing said polyester resin; forming an assembly of 30 superimposed sheets by placing said decorative sheet with the face surface uppermost upon a plurality of thermo4 5 4 6/1 - 25 setting resin impregnated substrate paper sheets; and consolidating the assembly with heat and pressure to form a unitary structure. 7. A process according to claim 6 wherein the decorative sheet after curing said resin, contains 35-55% by weight resin. 8. A process according to claim 6 or 7 wherein a melamine-formaldehyde resin impregnated sheet is positioned directly beneath said decorative sheet. 9. A process according to any one of claims 6 to 8 wherein said polyester resin is cured to a semi-solid state by radiation. 10. A process according to any one of claims 6 to 9 wherein the viscosity of the polyester resin at the time of its application to the decorative sheet ranges between 300 and 3000 centipoise. 11. A process according to any one of claims 6 to 9 wherein the viscosity of the polyester resin at the tine ox its application to the decorative sheet ranges between 700 and 3000 centipoise. 12. A process for producing a decorative laminate comprising the steps of applying a polyester resin to a decorative paper sheet and partially curing the resin, placing beneath the decorative sheet a plurality of thermosetting resin impregnated paper sheets, said thermosetting resin being separated from said cured resin by a dry sheet portion comprising either a part of said decorative sheet, or a dry paper sheet interposed between said decorative sheet and said resin impregnated sheets, and consolidating the assembly with heat and pressure to form a unitary laminated structure. - 26 13. A process for producing a decorative laminate comprising the steps of applying a polyester resin to the face surface of a decorative paper sheet to impregnate the sheet and drying the polyester resin, coating a release 5 sheet with a polyester resin and partially curing the resin coating on the release sheet, preparing an assembly of superimposed sheets by placing the release sheet upon the decorative paper meet with the resin coating of the release sheet in contact with the face surface of the 10 decorative paper sheet, placing the decorative paper sheet on a dry paper sheet and placing a plurality of thermosetting resin impregnated paper sheets beneath said dry paper sheet, consolidating said assembly under heat and pressure to form a unitary laminated structure, and 15 removing the release sheet from said structure. 14. A process for producing a decorative laminate comprising the steps of applying a polyester resin to the face surface of a decorative paper sheet, allowing a portion of said resin to penetrate into said sheet a 20 distance less than the thickness thereof and drying said resin, coating a release sheet with a polyester resin and partially curing the resin coating on the release sheet, preparing an assembly of superimposed sheets by placing the release sheet upon the decorative paper sheet with the 25 resin coating of the release sheet in contact with the face surface of the decorative sheet and placing a plurality of thermosetting resin impregnated paper sheets beneath said decorative sheet, consolidating said assembly under heat and pressure to form a unitary laminated structure, 30 and removing the release sheet from said structure. 15. A process for producing a decorative laminate comprising the steps of applying a polyester resin mixture containing from 85% to 95% by weight resin and 5% to 15% by Weight vinyl monomer to a decorative paper sheet, a ΰ 1 6 i - 27 drying said resin mixture until the resin content of said sheet is from 40% to 63% by weight of the dried impregnated decorative paper sheet, coating a release sheet with a polyester resin to a thickness between 10 5 and 20 mils and curing the resin to a B stage as herein defined; preparing an assembly of superimposed sheets by placing said decorative paper sheet upon a dry paper sheet, placing the release sheet upon the decorative paper sheet with said resin coating in direct contact 10 therewith and placing beneath said dry paper sheet a plurality of thermosetting resin impregnated paper sheets: consolidating said assembly under heat and pressure to form a unitary laminated structure, and removing the release sheet from said structure. 15 16. A process according to claim 15 wherein said polyester resin impregnates substantially the entire decorative sheet. 17. A process according to claim 15 or claim 16 wherein a melamine-formaldehyde resin impregnated paper sheet 20 is positioned directly beneath said dry paper sheet. 18. A process according to claim 15, 16 or 17 wherein a polyester impregnated paper barrier sheet is Inserted directly above said dry paper sheet. 19. A process for producing a decorative laminate comprising the steps of applying a polyester resin to the face surface of a dry decorative paper sheet to a thickness between 17 and 30 mils and allowing a portion of said resin to penetrate into said sheet a distance less than the thickness thereof, partially curing said polyester resin to a 'B' stage as herein defined until the resin content of said sheet is between 75% and 85% by weight of the partially cured impregnated sheet, forming an assembly of super30

4. S461 -· 28 imposed sheets by placing said decorative paper sheet with the face surface uppermost upon a dry paper sheet and placing a plurality of thermosetting resin impregnated paper substrate sheets therebeneath; and, consolidating

5. The assembly with heat and pressure to form a unitary structure. 20. A process according to claim 19 wherein a melamine-formaldehyde resin impregnated paper sheet is positioned 'directly beneath said dry paper sheet.

6. 10 21. A process according to claim 19 or claim 20 wherein the viscosity of the polyester resin at the time of its application to she decorative sheet ranges between 300 and 3000 centipoise. 22. A process according to claim 19 or claim

7. 15 20 wherein the viscosity of the polyester resin at the time of its application to the decorative sheet ranges between 700 and 3000 centipoise. 23. A process according to any one of claims 19 to 22 wherein a polyester impregnated paper barrier

8. 20 sheet is placed directly above said dry paper sheet and below said decorative paper sheet.

9. 24. A process for producing a decorative laminate substantially as herein described in Example 1.

10. 25. A process for producing a decorative 25 laminate substantially as herein described in Example 2.

11. 26. A process for producing a decorative laminate substantially as herein described in Example 3.

12. 27. A process for producing a decorative laminate substantially as herein described in Example 4. - 29

13. 28. A process for producing a decorative laminate substantially as herein described in Example 5.

14. 29. A process for producing a decorative laminate substantially as herein described in Example 6. 2

15. 30. A process fcr producing a decorative laminate substantially as herein described in Example 7.

16. 31. A process for producing a decorative laminate substantially as herein described in Example 8.

17. 32. A process for producing a decorative laminate 10 substantially as herein described in Example 9.

18. 33. A process for producing a decorative laminate substantially as herein described in Example 10.

19. 34. A process for producing a decorative laminate substantially as herein described in Example 11. 1.5

20. 35. A process for producing a decorative laminate substantially as herein described in Example 12.

21. 36. A process for producing a decorative laminate substantially as herein described in Example 13.

22. 37. A process for producing a decorative laminate 20 substantially as herein described in Example 14.

23. 38. A process for producing a decorative laminate substantially as herein described in Example 15. «

24. 39. A process for producing a decorative laminate substantially as herein described in Example 16.

25. 40. A process for producing a decorative laminate - 30 substantially as herein described in Example 17.

26. 41. A process for producing a decorative laminate substantially as herein described in Example 18.

27. 42. A process for producing a decorative laminate 5 substantially as herein described in Example 19.

28. 43. A process for producing a decorative laminate substantially as herein described in Example 20.

29. 44. A process for producing a decorative laminate substantially as herein described in Example 21. 10

30. 45. A process for producing a decorative laminate substantially as herein described in Example 22.

31. 46. A decorative laminate formed by a process according to any one of the preceding claims.